Tennessee Code Title 55. Motor and Other Vehicles § 55-52-105

(1) For any person under sixteen (16) years of age to operate or be a passenger on a bicycle unless at all times when so engaged the person wears a protective bicycle helmet of good fit fastened securely upon the head with the straps of the helmet;

(2) For any person to be a passenger on a bicycle unless, with respect to any person who weighs less than forty pounds (40 lbs.), or is less than forty inches (40″) in height, the person can be and is properly seated in and adequately secured to a restraining seat;

(3) For any parent or legal guardian of a person under twelve (12) years of age to knowingly permit the person to operate or be a passenger on a bicycle in violation of subdivision (1) or (2); and

(4) To rent or lease any bicycle to or for the use of any person under sixteen (16) years of age unless: